cpqDaLogDrvPerfCacheMisses reports the total number of read cache misses for a logical volume, expressed in cache misses per second. A rising miss rate alongside falling cache hits means more read requests are having to go all the way to the physical disks, which increases latency. For example, an admin noticing cache misses climbing on a volume during a specific time of day would correlate that with whatever batch job runs then to see if it's flushing useful data out of cache.